/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraEmitter.h
Callback issued whenever a VM compilation successfully happened (even if the results are a script that cannot be executed due to errors)
[FOnEmitterCompiled](API\Plugins\Niagara\UNiagaraEmitter\FOnEmitterCompiled) & OnEmitterVMCompiled()